The invention relates to a magnetic head including a core of a magnetic material having two parts which are spaced apart so that a non-magnetic transducing gap is formed which is bounded on one side by a winding aperture which extends in the gap-bounding surface of at least one of the core parts and narrows towards the transducing gap. The invention further relates to a method of manufacturing such a magnetic head.
Such a magnetic head is known from DE Offenlegungsschrift 26 34 156, to which U.S. Pat. No. 4,045,864 corresponds. In the manufacture of this known magnetic head, the (groove-shaped) winding aperture is provided by means of a grinding operation in the core part in question. Initially, the core part together with a number of further core parts of the same shape form a block of magnetic material. In an accurately worked surface thereof, a longitudinal groove is provided by means of a profiled disc. The block with said grooved surface is cemented against a second block, the bonding means used forming a non-magnetic (transducing) gap. The assembly of the two blocks is given a curved tape-contact face in a further stage of the manufacture by means of a grinding and polishing process. During the grinding/polishing operation so much of the core material is removed that a gap remains between the core parts having a desired gap height. The edge of the groove facing the gap is used in measuring the gap height. It will be obvious that the accuracy with which said edge is formed determines the accuracy with which the gap height can be adjusted. In video heads, a gap height of 50 .mu.m is usual and inaccuracies in the position of the edge (caused by crumbling away of core material as a result of the grinding process) should not be more than 5 .mu.m.
Grinding a groove in the core material (usually ferrite) with such a great precision is very difficult.